Media devices, which may take the form of set top boxes (STBs), are configured to deliver one or more selected media content events to an audio and/or visual device. Typically, the media device connects to a television and an external signal source in which the signal (e.g., cable signal) is converted to viewable media content. However, the media device may operate with other types of audio or visual devices, which may take the form of, but are not limited to, televisions (TVs), personal computers (PCs), stereos, personal digital assistants (PDAs), surround-sound systems, and digital video recorders (DVRs). Particular media content events may be selected by a user who provides instructions or commands to the media device. For example, if the media content event is a movie, the video portion of the movie is displayed on a display of the TV, the PC, or the like. The audio portion of the movie may concurrently be presented over the speakers of the TV, the stereo, or the surround-sound system. In some instances, the media content event may be stored into a DVR or other recording device for later retrieval and presentation. The DVR may be an integrated component of the media device, or the DVR may be a stand-alone device that is communicatively coupled to the media device.
For a variety of reasons such as consumer demand, portability, spatial constraints and aesthetics, the tendency in the marketplace has been toward more streamlined components still capable of providing a high quality media content (e.g., flat screen televisions and small, wall mounted speakers). However, one of the continual challenges of making a low profile, streamlined media device is the effective transfer of heat away from heat-generating components mounted on a printed circuit board (PCB) or alternatively the effective insulation of a component adjacent to or in a vicinity of heat-generating component. Conventional media devices typically have an active cooling system employing one or more fans or blowers to move air through media device. One drawback of a conventional fan system is the amount of space (e.g., internal spatial envelope) needed within the media device to mount and adequately operate the fan. Thermal insulation, on the other hand, is usually accomplished using various pastes, epoxies, potting compounds, coatings or laminates, which may be effective, but are dependent upon assembly accuracy and internal tolerances.
Lastly, it is common practice to provide thermal pads on the PCB to obtain the requisite heat transfer from a heat generating component to the PCB. For example, conventionally mounting of a Quad Flat No leads (QFN) package or a Dual Flat No leads (DFN) package include arranging exposed thermal pads on the PCB to improve heat transfer out of the chip into the PCB, preferably by way of metal vias in the thermal pads. However, the design and implementation of thermal pads requires that many factors are in balance, such as, but not limited to, the solder paste coverage in the thermal pad region, stencil design for peripheral and thermal pad regions, type and size of the vias, circuit board thickness, surface finish on the circuit board, and cracking due to thermal or mechanical stresses around the thermal pad regions.